论文标题
自洽的筛选增强了非平衡激发剂阶段的稳定性
Self-consistent screening enhances stability of the nonequilibrium excitonic insulator phase
论文作者
论文摘要
非平衡激素绝缘子（NEQ-EI）是一种激发的物质状态，其特征是有限的相干激子密度和时间依赖性的宏观极化。随着密度的增长，这种激子超流体的稳定性因较宽的激子的筛选效率的提高而受到危害。在这项工作中，我们提出了一个Hartree Plus筛选的Exchange HeSES方案，以预测向自由电子血浆过渡发生的临界密度。使用NEQ-EI偏振来自兼介电函数，并在长波长极限中消失。该属性使激子超流量稳定至相对较高的密度。 MOS $ _ {2} $单层的数值结果表明，NEQ-EI阶段可以生存至$ 10^{12} \ Mathrm {cm}^{ - 2} $的订单密度。
The nonequilibrium excitonic insulator (NEQ-EI) is an excited state of matter characterized by a finite density of coherent excitons and a time-dependent macroscopic polarization. The stability of this exciton superfluid as the density grows is jeopardized by the increased screening efficiency of the looser excitons. In this work we put forward a Hartree plus Screened Exchange HSEX scheme to predict the critical density at which the transition toward a free electron-hole plasma occurs. The dielectric function is calculated self-consistently using the NEQ-EI polarization and found to vanish in the long-wavelength limit. This property makes the exciton superfluid stable up to relatively high densities. Numerical results for the MoS$_{2}$ monolayers indicate that the NEQ-EI phase survives up to densities of the order of $10^{12}\mathrm{cm}^{-2}$.
